--- a/dyncall/dyncall_callvm_x64.c	Wed Jan 08 02:39:45 2020 +0100
+++ b/dyncall/dyncall_callvm_x64.c	Wed Jan 08 17:10:17 2020 +0100
@@ -194,11 +194,13 @@
 #include <assert.h>
 void dc_callvm_call_x64_syscall_sysv(DCCallVM* in_self, DCpointer target)
 {
+  DCCallVM_x64* self;
+
   /* syscalls can have up to 6 args, required to be "Only values of class INTEGER or class MEMORY" (from */
-  /* SysV manual), so we can use self->mRegData.i directly; verify this holds at least 6 values, though. */
+  /* SysV manual), so we can use self->mRegData.i directly; verify this has space for at least 6 values, though. */
   assert(numIntRegs >= 6);
 
-  DCCallVM_x64* self = (DCCallVM_x64*)in_self;
+  self = (DCCallVM_x64*)in_self;
   dcCall_x64_syscall_sysv(self->mRegData.i, target);
 }